tl;dr, how can I bundle a gratis but closed-source game in an otherwise BSD 2 clause licensed free software project?
I develop a free software project which is licensed under the BSD 2 clause license....

I have a python project licensed under BSD-License.
On its bottom I use a source code written in C++ which is licensed as LGPL and I have an optional dependency on a python package licensed under GPL.
...

There is an editor Draft.js. It's licensed under the BSD-style License. Every file in the source code has a copyright notice. Here is a piece of that notice:
* This source code is licensed under the ...

I have a BSD-licensed piece of code, and I would like to integrate some code licensed under the Boost software license directly in the file, for reasons of portability. The file contains the full BSD ...

I am planning to develop commercial software product that will include a few open-source libraries licensed under different licenses (licenses for different libraries different):
MIT,
Apache Software ...